The Core Facility is designed to serve several Projects of this Program Project Grant of the Institute for Genetic Medicine. Each of the served Projects requires routine as well as highly specialized rodents. These Projects require inbred mouse strains and specialized facilities for the care of athymic nude mice, scid mice and rats. These projects share a need for careful tumor passaging and growth by implantation or tail vein delivery. This Core will provide reliable routine measurements and monitoring of tumor growth and the effects of the cellular gene therapy methods being employed. The Animal Models Core will also provide centralized and cost effective histopathology services for the multiple Project groups at the site of the animal facility. This Core was established to provide a cost effective and centralized service for development and use of animal models that may lead to effective gene therapies for cancer.